Bug 58339 – Apple movie trailers play only audio

• Component: Media
• Status: RESOLVED FIXED

[Eric Carlson]

Movie trailers at http://trailers.apple.com play only audio on OS X 10.7 unless the time is changed manually by dragging the timeline thumb.

[Eric Carlson]

<rdar://problem/9237606>

[Eric Carlson]

This happens because HTMLVideoElement::setDisplayMode assumes that a frame of video will be available immediately after calling a media engine's prepareForRendering function. This is not necessarily the case with AVFoundation so HTMLVideoElement continues to display the @poster, which is a 1x1 white pixel.

The solution is to add a mechanism for a media engine to let HTMLMediaElement know when the first frame is ready to render.

[Eric Carlson]

Created attachment 89286 [details]
Proposed patch.

[Jer Noble]

Comment on attachment 89286 [details]
Proposed patch.

View in context: https://bugs.webkit.org/attachment.cgi?id=89286&action=review

> Source/WebCore/platform/graphics/avfoundation/MediaPlayerPrivateAVFoundation.cpp:494
> +    if (!m_haveReportedFirstVideoFrame && m_cachedHasVideo && hasAvailableVideoFrame()) {
> +        m_haveReportedFirstVideoFrame = true;
> +        m_player->firstVideoFrameAvailable();
> +    }
> +

Is -[AVPlayerLayer isReadyForDisplay] KVO-compliant?  Because it seems a shame we have to wait for some other notification before checking to see if there's a frame ready to be rendered.
...
Apparently it is observable.  You could add a new observer so that we run through updateStates() as soon as a frame is ready.  But that's just an optimization and not strictly necessary.

Looks good to me.

[Simon Fraser (smfr)]

Comment on attachment 89286 [details]
Proposed patch.

r=me with a comment in email

[Eric Carlson]

http://trac.webkit.org/changeset/83667